Centralgin General Information

A narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. Prolonged use may lead to dependence of the morphine type; withdrawal symptoms appear more rapidly than with morphine and are of shorter duration. .[PubChem].

Centralgin - Pharmacology:

Centralgin is primarily a kappa-opiate receptor agonist and also has local anesthetic effects. Centralgin has more affinity for the kappa-receptor than morphine. Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Centralgin's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.

Centralgin Interactions

Interaction with Other Central Nervous System Depressants: MEPERIDINE SHOULD BE USED WITH GREAT CAUTION AND
IN REDUCED DOSAGE IN PATIENTS WHO ARE CONCURRENTLY RECEIVING OTHER NARCOTIC ANALGESICS, GENERAL ANESTHETICS,
PHENOTHIAZINES, OTHER TRANQUILIZERS, SEDATIVE-HYPNOTICS (INCLUDING BARBITURATES), TRICYCLIC ANTIDEPRESSANTS AND OTHER
CNS DEPRESSANTS (INCLUDING ALCOHOL). RESPIRATORY DEPRESSION, HYPOTENSION, AND PROFOUND SEDATION OR COMA MAY
RESULT.

Centralgin Contraindications

Hypersensitivity of meperidine.

Centralgin is contraindicated in patients who are receiving monoamine oxidase (MAO) inhibitors or those who have
recently received such agents. Therapeutic doses of meperidine have occasionally precipitated unpredictable, severe,
and occasionally fatal reactions in patients who have received such agents within 14 days. The mechanism of these
reactions is unclear, but may be related to a preexisting hyperphenylalaninemia. Some have been characterized by
coma, severe respiratory depression, cyanosis, and hypotension, and have resembled the syndrome of acute narcotic
overdose. In other reactions the predominant manifestations have been hyperexcitability, convulsions, tachycardia,
hyperpyrexia, and hypertension. Although it is not known that other narcotics are free of the risk of such reactions,
virtually all of the reported reactions have occurred with meperidine. If a narcotic is needed in such patients, a
sensitivity test should be performed in which repeated, small, incremental doses of morphine are administered over
the course of several hours while the patients condition and vital signs are under careful observation. (Intravenous
hydrocortisone or prednisolone have been used to treat severe reactions, with the addition of intravenous
chlorpromazine in those cases exhibiting hypertension and hyperpyrexia. The usefulness and safety of narcotic
antagonists in the treatment of these reactions is unknown.)